Re: [PATCH] submodule--helper: teach push-check to handle HEAD

[Stefan Beller <sbeller@google.com>]

On Fri, Jun 23, 2017 at 1:04 PM, Brandon Williams <bmwill@google.com> wrote:
> In 06bf4ad1d (push: propagate remote and refspec with
> --recurse-submodules) push was taught how to propagate a refspec down to
> submodules when the '--recurse-submodules' flag is given.  The only refspecs
> that are allowed to be propagated are ones which name a ref which exists
> in both the superproject and the submodule, with the caveat that 'HEAD'
> was disallowed.
>
> This patch teaches push-check (the submodule helper which determines if
> a refspec can be propagated to a submodule) to permit propagating 'HEAD'
> if and only if the superproject and the submodule both have the same
> named branch checked out and the submodule is not in a detached head
> state.

cont'd:

We need this use case because Gerrit's documentation ingrains
this workflow in its users to use

    git push <remote> HEAD:refs/for/<target-branch>

And when both the submodule as well as the superproject
are still on a branch with the same name (and not detached) we'd
not be misunderstood by the user on the syntax.

More on the code later.